Tapered helically reinforced hose and its manufacture

ABSTRACT

Flexible tubing or hose is formed from continuously extruded thermoplastic material helically circumferentially wound at a wrapping station around an array of bearing-supported rods that are concurrently but individually turned and are canted relative to an imaginary central axis. The tubing or hose is formed to have a continuous reinforcing rib helically wound therearound and continuously integrally connected thereto. The positions of the rods are progressively altered during formation of at least a contiguous portion of the tubing or hose, causing the resulting contiguous portion to exhibit a progressive continuous change in diameter. The resulting tubing or hose may be transversely severed at intervals along its length, and may be flattened to form cuffs near where severed. A selected portion of the tubing or hose, which may or may not at least partially coincide with the contiguous portion, may be axially compressed and annealed to relieve stress therein.

REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of co-pending U.S. patent applicationSer. No. 13/507,172 filed Jun. 11, 2012 by the same inventors namedherein and with the same title, the disclosure of which is incorporatedherein by reference.

U.S. patent application Ser. No. 13/507,172 claims the benefit of U.S.Provisional Application Ser. No. 61/627,425 entitled TAPERED FLEXIBLEHOSE AND METHOD OF MANUFACTURE filed Oct. 12, 2011 by Carl J. Garrett,Donald K. Hadley and Martin E. Forrester, the disclosure of which isincorporated herein by reference.

U.S. patent application Ser. No. 13/507,172 is also aContinuation-in-Part of U.S. patent application Ser. No. 12/799,263 (nowissued as U.S. Pat. No. 8,453,681) entitled FLEXIBLE, STRETCHABLE, CRUSHRESISTANT HOSE WELL SUITED FOR MEDICAL APPLICATIONS filed Apr. 21, 2010by Martin E. Forrester and Ralf Jourdan, the disclosure of which isincorporated herein by reference.

U.S. patent application Ser. No. 12/799,263 claims the benefit of U.S.Provisional Application Ser. No. 61/335,023 entitled FLEXIBLE HOSE FORMEDICAL APPLICATIONS filed Dec. 30, 2009 by Martin E. Forrester, thedisclosure of which is incorporated herein by reference.

BACKGROUND

The present invention relates to helically reinforced tubing or hose,and to an apparatus for and method of production of tubing or hosehaving characteristics that may progressively vary along continuousselected lengths of the tubing or hose, thereby enabling the resultingtubing or hose to incorporate lengths that increase or diminish indiametrical size, wall thickness and pitch, as may be desired for use inspecific applications.

Tapered tubing or hose has many proposed commercial, industrial andmedical uses. Commercially, a tapered length of tubing or hose can beused to improve air flow and reduce the accumulation of debris withinthe tubing or hose. An aspect of the invention permits tapered tubing orhose to be provided with a helical reinforcing rib that may be formedinto a substantially constant diameter rigid or semi-rigid cuff nearwhere severed to provide end regions that may connect with existingfittings or devices, or for use as a wand to vacuum yard debris fromaround obstacles, or as a wand to direct high velocity air generated byleaf blowers or blowing equipment that delivers seed, mulch, insulationor the like. Another aspect of the invention permits a tapered region oftubing or hose to be designed with a correct taper length, curve orangle to provide a desired air or gas velocity for substantially anygiven application.

Industrially, tapered tubing or hose can be used to eliminate the needfor multiple connectors and adapters in fume exhaust systems as theinside diameter can be varied to create a proper air flow and velocityfor any given application—which will also diminish the overall weightand cost of the system. Likewise, substantially the same designprincipal can be used to provide tapered tubing or hose to transportsuch items as grain or other granular materials including plasticpellets and other “flowable” raw materials.

Medically, a tapered, lightweight, highly flexible tubing or hose (whichcan be relatively easily and continuously produced by the techniques ofthe present invention) is useful for exhausting gases from areas wheresurgery is being performed, and is especially useful in providingbreathing conduits used with sleep apnea equipment and other medicaldevices related to breathing.

One particularly desirable use of tapered tubing or hose manufactured inaccordance with features of the present invention has to do with thetreatment of sleep apnea. Thousands of people suffer from sleep apnea,which causes those who have the affliction to repeatedly stop breathingwhile they sleep, sometimes hundreds of times a night. Breathing pausescan occur more than 30 times per hour, and may each last several secondsor may continue for a minute or more. The result is that those who havesleep apnea are more likely to be involved in accidents, and they are atrisk for such complications as diabetes, heart disease and stroke.

Sleep apnea results from a closure of the airway of the person who hasthe affliction. A common treatment for sleep apnea centers about keepinga patient's airway open during sleep through use of a “ContinuousPositive Airway Pressure” unit that blows air into a person'snose—sometimes the mouth, too—forcefully enough to keep the back of thethroat open. In simple terms, a so-called “CPAP machine” includes apump, a length of tubing or hose, and a face mask.

The tubing or hose of a CPAP machine consists of either a single largediameter length of tubing or hose running from the pump to the mask, ora relatively large diameter length of tubing or hose running from thepump to a combination swivel coupling and reducer fitting located about18 to 24 inches away from the mask, where tubing or hose diameter isreduced or diminished to provide a more flexible length of tubing orhose leading to the mask that still is able to provide adequate air flowand pressure.

While CPAP machines have gotten smaller, quieter and more sophisticatedover the years, about half of the patients who need them can't or won'tuse them, for a variety of reasons. For example, the mask can beclaustrophobic, get in the way of glasses, or may fall off during thenight. The tubing or hose that delivers air to the mask may preventsomeone from sleeping on his or her stomach, or from rolling over.Indeed, many of those who have tried to use CPAP machines havecomplaints about the awkward nature of the air supply tubing or hose,which often result in these machines being used mainly as doorstops.

By replacing the clumsy combination of a larger then smaller diametertubing or hose (typically joined by a combination of swivel connectorsand reducer fittings) with quite a simple and lightweight, one-piecereach of tapered tubing or hose, CPAP units can be provided with a muchimproved, easy-to-flex breathing circuit, thereby rendering thesemachines far more acceptable for use by patients who need them. Iiiaccordance with features of the present invention, a tapered length ortubing or hose can be provided for CPAP machines, with the tubing orhose having such characteristics as variable pitch, wall thickness andhelix size that is designed to achieve a much more desirable feel andprovide an easier flow of air than provided by the presently usedarrangement of a dual diameter set of tubes or hoses joined by acombination reducer and swivel coupling. Indeed, in accordance withfeatures of the present invention, a tapered length of tubing or hosefor use with a CPAP machine can be manufactured in such a way as toreduce or to even eliminate a pressure drop along the length of a tubingor hose circuit, or to increase or decrease air velocity or pressure inthe tubing or hose circuit, as desired.

It is also possible, using features of the present invention, to provideCPAP machines with a one-piece, helically reinforced tapered length oftubing or hose of any desired diameter or having a desired change indiameter provided anywhere that is desired along the length of thetubing or hose, perhaps including an enlarged “belly” (i.e., an area ofsignificantly enlarged diameter) for use as a decompression chamber,water trap or accumulator, which some patients require. Likewise,variable diameter flexible tubing or hose products produced usingtechniques of the present invention give a designer of tubing or hosesystem circuitry many options not currently available without the use ofclumsy couplings and fittings that add cost and weight to a tubing orhose system while reducing flexibility and other desired performancecharacteristics.

SUMMARY

The present invention makes use of tubing or hose forming techniques ofthe general type described in U.S. Pat. No. 3,910,808 issued Oct. 7,1975, and U.S. Pat. No. 3,966,525 issued Jun. 29, 1976 to William L.Steward, but advances the technology significantly beyond what isdisclosed or suggested in the referenced Steward patents, thedisclosures of which are incorporated herein by reference, in theirentirety.

One aspect of the present invention relates to formation of a helicallyreinforced tubing or hose that includes along its length at least oneportion, reach or region that changes substantially continuously andprogressively in diameter (i.e., in diametrical size) so as to taper asdesired—for example, by providing a taper that exhibits a truncated conein shape, or that is convex, concave, or bulbous in configuration andappearance. A length of tubing or hose that embodies features of theinvention may have other portions, reaches or regions that are ofsubstantially constant diameter, or that may vary, taper or changesubstantially continuously and progressively in diametrical size.

Other aspects of the invention relate to an apparatus for and method ofproducing helically reinforced tubing or hose that may feature any of awide range of substantially continuously and progressively changingcharacteristics such as diameter and wall thickness—characteristics thatchange progressively along at least a continuous portion of the lengthof the tubing or hose. The method and apparatus described in thereferenced Steward patents are not suited to the manufacture of tubingor hose lengths, or portions, regions and reaches thereof, that havecharacteristics including diametrical size which continuously andprogressively change or vary therealong.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, and a fuller understanding of the inventionmay be had by referring to the description and claims, taken inconjunction with the accompanying drawings, wherein:

FIG. 1 is a perspective view showing front portions of an apparatusembodying features of the present invention that may carry out methodfeatures of the invention to produce helically reinforced flexibletubing or hose that embodies product features of the invention;

FIG. 2 is another perspective view showing rear portions of theapparatus of FIG. 1;

FIG. 3 is an enlarged perspective view of selected components associatedwith the support and positioning of one of a plurality of spinning rodsarranged in an array within the apparatus of FIGS. 1 and 2;

FIG. 4 is an enlarged, schematic, sectional view showing how edgeportions of a web of extruded thermoplastic material overlap duringhelical winding to form a continuous wall of tubing or hose reinforcedby a helically wound bead or rib that is integrally continuously joinedwith the wall of the resulting tubing or hose;

FIG. 5 also is an enlarged schematic view illustrating how a tape-likeband of extruded thermoplastic is wrapped at a wrapping station in theapparatus of FIGS. 1 and 2 about a circular array of turning, rotatingor spinning rods;

FIG. 6 is a side elevational view of a length of tubing or hose that hasa straight-walled or truncated conical taper that transitions from arelatively smaller D₁ diameter to a relatively larger D₂ diameter, andthen has a straight-walled or truncated conical taper that transitionsback from the D₂ diameter to the D₁ diameter, and is transversely cut orsevered mid-way along spaced, constant diameter portions, regions orreaches that are of the D₁ and D₂ diameters;

FIG. 7 is a simplified side elevational view showing a portion of theapparatus of FIGS. 1 and 2 with rods that define a wrapping station setto form a tubing or hose portion, region or reach of relatively smallerdiameter;

FIG. 8 is a simplified side elevational view similar to FIG. 7, butshowing rods that define a wrapping station set to form a tubing or hoseportion, region or reach of relatively larger diameter;

FIG. 9 is a side elevational view of a length of tubing or hose thatincludes a concavely curved or tapered portion, region or reachtransitioning between tubing or hose portions, regions or reaches ofrelatively smaller and relatively larger diameters;

FIG. 10 is a side elevational view of a length of tubing or hose thatincludes a convexly curved taper transitioning between hose portions,regions or reaches of relatively smaller and relatively largerdiameters;

FIG. 11 is a side elevational view of a length of tubing or hose thatincludes a concave portion, region or reach transitioning between twotubing or hose portions, regions or reaches of equal and relativelylarge diameter; and,

FIG. 12 is a side elevational view of a length of tubing or hose thatincludes a convex portion, region or reach transitioning between twotubing or hose lengths of relatively equal and relatively smalldiameter.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, a tubing or hose manufacturing apparatusembodying features of the present invention is indicated generally bythe numeral 100. The apparatus 100 is used to continuously producehelically reinforced tubing or hose 102 at a wrapping station 103 thatis shown in FIG. 1. As the tubing or hose 102 is formed at the wrappingstation 103, the newly formed tubing or hose 102 not only turns, spinsor rotates about a central axis 101 but also moves along the centralaxis 101 (as indicated by an arrow 104) as the newly formed tubing orhose 102 departs from the wrapping station 103.

Continuous formation of tubing or hose by winding a continuouslyextruded web of thermoplastic material about an array of a plurality ofrods 110 that are individually concurrently turned, spun or rotated inunison in a same direction of rotation is in accord with a method andapparatus that are described in the referenced two above-referencedSteward patents. As is also described in the referenced Steward patents,the rods 110 about which tubing or hose 102 is formed are cantedrelative to the central axis 101; and, the rods 110 converge as theyextend from left to right (in FIGS. 1 and 2) toward the wrapping station103.

As is explained in the above-referenced Steward patents, the canting ofthe rods 110 assists a continuously extruded web of thermoplasticmaterial to wind in a helical manner about the rods 110, with an edgeregion of each newly wrapping convolution of hot, extruded thermoplasticmaterial slightly overlapping and promptly bonding to an edge region ofan adjacent, previously wound convolution to create a continuous,contiguously extending tubing or hose wall, and with a continuous beador rib of extruded thermoplastic material wound helicallycircumferentially externally around and continuously bonded to thetubing or hose wall to provide reinforcement.

The material from which the hose 102 is formed at the wrapping station103 preferably is hot, freshly extruded thermoplastic, typicallyextruded from a nearby die 107 of a conventional extrusion apparatus(not shown), in a manner well known to those who are skilled in the artof extrusion.

Heated thermoplastic material extruded under pressure from the die 107preferably includes a relatively flat, tape-like, continuous web 105that is of substantially uniform thickness—except that integrallyextruded with the web 105 may be a longitudinally extending reinforcingbead or rib 106, as is shown in the referenced Steward patents, that istypically wire-like in character so as to provide reinforcement whenwound around and bonded to a wall of tubing or hose 102. A wide range ofthermoplastics may form the extruded material that is helically wound atthe wrapping station 103, such as, but not limited to, polyvinylchloride (PVC), thermoplastic polyurethane (TPU), polypropylene (PP),thermoplastic elastomer (TPE) or acrylonitrile butadiene styrene (ABS)material.

It should be understood that the freshly extruded web 105 and thelongitudinally extending rib or wire-like bead 106 are hot and tackywhen they arrive at the wrapping station 103, and readily tend to adhereand bond promptly to each other as these materials are overlaid andhelically wound or wrapped to form the tubing or hose 102. A typicalmanner in which the web 105 and the rib or bead 106 are overlaid andhelically wrapped to form the tubing or hose 102 at the wrapping stationis depicted somewhat schematically in FIG. 4, and is also described andillustrated in the referenced Steward patents.

Referring to FIG. 4, it can be seen that only edge portions 98, 99 ofthe relatively flat, tape-like web 105 are overlaid and caused toimmediately bond—and that the wall of the newly formed hose 102 producedby the helically wound web 105 is overlaid and caused to be helicallyreinforced by the rib or wire-like bead 106 which is wrapped or woundcircumferentially around and bonded continuously and integrally to theperiphery or perimeter of the wall of the newly formed hose 102.

At the wrapping station 103, the arrayed rods 110 do not turn as a groupor as an array about the central axis 101. Rather, each of the identicalrods 110 is supported by a separate pair of spaced-apart sphericalbearings that enable the rods 110 to individually turn, spin or rotateabout their individual centerlines. The movable mounting of the bearingsthat support the rods 110 also enable the rods 110 to be moved radiallyrelative to the central axis 101, as will be explained in greater detailshortly.

As the hot, tacky, tape-like web 105 and the wire-like bead 106 arecaused to helically wrap about the array of the spinning rods 110, thespeed and direction of rotation at which the outer surfaces of the rods110 spin or turn corresponds to the direction of extrusion ofthermoplastic material toward the wrapping station 103, and at leastequals or exceeds the speed of the moving extrusion. Preferably, thesurface speed of the turning rods 110 at least slightly pulls orstretches the extruded thermoplastic to narrow and relatively tightlywrap the extruded thermoplastic material circumferentially about thearray of turning or spinning rods 110.

Schematically depicted in FIG. 5 is the manner in which the spinningrods 110 are positioned in a circular array 109 at the wrapping station103. Also shown is how the spinning rods 110 receive the tape-like band105 and cause the band 105 to helically wrap circumferentially aroundthe array 109 of spinning rods 110 and bond where edge portions of theweb 105 of extruded material overlap to thereby form a continuous,uninterrupted tubular wall of the hose 102. At the wrapping station 103,each of the rods 110 is identically positioned and spaced from thecentral axis 101. The rods 110 turn concurrently, in unison, in a samedirection of rotation, as indicated by arrows 95, giving the rods 110 asurface velocity that is adjusted to match or slightly exceed thevelocity at which the web 105 is fed from the extrusion die 107 locatedat one side of the central axis 101 in a direction generally toward thewrapping station 103. The extruded web 105 is wound or wrapped in themanner indicated by the arrows 96.

In the example illustrated by FIGS. 1, 2 and 5, the relatively closepositioning of the rods 110 causes distances between adjacent ones ofthe spinning rods 110 to be relatively small, enabling only four of thespinning rods 110 of relatively small diameter to be used to form tubingor hose 102 of relatively small diameter. If, however, tubing or hose102 of significantly larger diameter (not shown) is to be formedutilizing the technique described above, a larger number of the spinningrods 110, and/or spinning rods 110 of somewhat larger diameter, may beused, with adjacent ones of the rods 110 spaced equidistantly andidentically positioned relative to the central axis 101, so that thetubing or hose 102 being formed does not collapse as the tape-like band105 and the rib or wire-like bead 106 are being wrapped about the array109 of spinning rods 110 at the wrapping station 103.

A smaller number of the spinning rods 110 and/or rods 110 of smallersize can be provided if tubing or hose 102 of a quite small diameter(not shown) is to be formed at the wrapping station 103. A larger numberof the spinning rods 110 may be utilized if tubing or hose of largerdiameter is to be formed at the wrapping station 103.

As those skilled in the art of extrusion will readily appreciate, thetape-like band of thermoplastic material 105 and the rib or wire-likebead 106 of extruded thermoplastic material may be extruded fromentirely separate supplies (typically from separate extruders, notshown), which is particularly useful if it is desired that the materialsof the tape-like web 105 and the wire-like bead 106 be formed fromdifferent thermoplastics. However, in the example depicted in thedrawings, a common thermoplastic is used to form both of the materials105, 106, and the continuous lengths 105, 106 are thereforesimultaneously extruded from a single conventional extruder (not shown)through the single die 107.

By controlling the quantity and velocity of the output of moltenthermoplastic from the extruder die 107, a consistent continuous supplyof thermoplastic material is preferably provided forming the tape-likeband 105 and the wire-like bead 106, thereby insuring that the tubing orhose 102 formed at the wrapping station 103 has a desirably uniform wallthickness with a desired type of helical reinforcement extendingtherearound and bonded thereto.

The apparatus 100 that supports and spins the rods 110 includes a motor120 that powers a gearbox 130 that has an adequate number of outputshafts 131 so that each output shaft 131 can spin, turn or rotate adifferent one of the rods 110 of the array 109. A gearbox 130 having alarger number of output shafts 131 is used if more than four spinningrods 110 are to comprise the rod array 109. Likewise, a gearbox 130having a smaller number of output shafts 131 is used if less than fourspinning rods 110 are to comprise the rod array 109.

The output shafts 131 are each connected by a flexible linkage 132 witha rear end region of a different one of the four rods 110, to cause therods 110 to spin, while also permitting the spinning rods 110 to bemovably positioned by identical rear and front slides 140, 150 (atypical one of which is indicated by the numeral 150 in FIG. 3) thatcarry identical rear and front spherical bearings (a typical one ofwhich is indicated by the numeral 154 in FIG. 3) that journal rear andfront portions of each of the rods 110, respectively.

As has been explained, the spinning of the rods 110 helps to cause thefreshly extruded thermoplastic material that is extruded toward thearray 109 of rods 110 to wrap about the rod array 109 at the wrappingstation 103. By controlling speed of the motor 120 (and hence the spinspeed of the rods 110), the production rate of the tubing or hose 102 iscontrolled to provide a resulting tubing or hose product 102 thatexhibits desired characteristics.

Referring to FIG. 2, the rods 110 extend forwardly from where theyconnect with the linkages 132, to extend through rear spherical bearingsthat are carried by a set of rear slides 140 which are movable indirections radially toward and away from the central axis 101 alongradially extending rear trackways 141 that are defined by a rear housingmember 142. Referring to FIG. 1, the rods 110 extend still fartherforwardly to where they extend through front spherical bearings 154(FIG. 3) that are carried by a set of front slides 150 (FIGS. 1 and 3)which also are movable radially in directions toward and away from thecentral axis 101 along radial front trackways 151 that are defined by afront housing member 152.

As can best be seen in FIG. 2, four rear servo motors 143 are providedon the rear housing member 142 to move the four rear slides 140 radiallytoward and away from the central axis 101 along the four rear trackways141 that are defined by the rear housing member 142. Each of the servomotors 143 moves a different one of the rear slides 140. Likewise, ascan best be seen in FIG. 1, four front servo motors 153 are carried bythe front housing member 152 to individually radially move the frontslides 150 along the four front trackways 151 that are defined by thefront housing member 152.

By concurrently operating the four rear motors 143 in unison, and byconcurrently operating the four front motors 153 in unison, the rods 110may be moved radially (i.e., they may be repositioned radially) whilemaintaining the slides 110 at equal distances from the central axis 101.By adjusting the positions of the rear and front slides 140, 150 alongthe rear and front radially extending trackways defined by the rear andfront housings 142, 152, respectively, the portions of the spinning rods110 about which the freshly extruded thermoplastic materials 105, 106are wrapped at the wrapping station 103 can cause tubing or hose ofsmaller or larger diameter to be formed at the wrapping station.

Preferably, the rear and front slides 140, 150 are of identicalconfiguration, as are the rear and front spherical bearings that arecarried by the slides 140, 150. Likewise, the rear and front motors 143,153 are identical, as are the output shafts of the motors 143, 153 thatconnect with and cause movement of the rear and front slides 140, 150along the rear and front radially extending trackways 141, 151,respectively.

A typical one of the slides 150 is shown in FIG. 3 carrying a typicalspherical bearing 154. A typical one of the motors 153 also is shown inFIG. 3 as having an output shaft 155 that is threaded into an associatedone of the slides 150. Rotation of the output shaft 155 in one directioncauses the slide 150 to move toward the central axis 101. Rotation ofthe shaft 155 in the opposite direction causes the slide 150 to move inan opposite direction away from the central axis 101.

As can be seen by comparing the positions of the rear and front motors143, 153 in FIGS. 1 and 2, the rear and front trackways 141, 151 thatare defined by the rear and front housings 142, 152, respectively, aretypically not aligned. Stated in another way, the rear trackways 141along which each of the rear slides 140 move are, in essence, “canted”relative to the front trackways 151 along which each of the front slides150 move. The extent to which these rear and front trackways 141, 151are canted held out of alignment is determined by a servo motor 160carried by the front housing member 152, which causes the rear housingmember 142 to turn about the central axis 101 (to a small and limitedextent) relative to the front housing member 152 (which is fixed andtherefor does not turn about the axis 101).

The motor 160 drives an output gear 161 that meshes with and drives amuch larger gear 162 that rings and is connected to the rear housingmember 142. Rotation of the output gear 161 of the motor 160 causes thelarge gear 162 to turn slightly about the central axis 101, therebycausing the four planes in which the rear trackways 141 extend to cantturn either relatively closer into alignment with, or relatively fartherout of alignment with, the four planes in which the front trackways 151extend. By controlling the extent to which the rear trackways 141 arecanted relative to the front trackways 151, the extent to which edgeportions 98, 99 of the tape-like band 105 overlap (as shown somewhatschematically in FIG. 4) is controlled. Stated in another way, thehelical wrapping of the tape-like band 105 and the wire-like bead 106 iscaused to take place, and its character is controlled by the servo motor160 which causes the rods 110 to be canted relative to the center axis101.

A significant feature of the present invention resides in therealization that the needed canting of the rods 110 that define thewrapping station 103—the rods 110 about which extruded thermoplasticmaterial is wound—can be nicely controlled by simply relatively turningthe front and rear housing members 152, 142 about the center axis 101.Although the referenced Steward patents recognize the need for cantingrods about which extruded thermoplastic is wound, the Steward patents inno way teach or suggest that the needed rod canting can be providedsimply by relatively turning two housing members that support front andrear sets of bearings that journal the rods for rotation.

Nor do the referenced Steward patents teach or suggest that needed rodcanting can be adjusted or modified by relatively turning two housingmembers about a central axis along which newly formed hose travels as itexits a wrapping station defined by the spinning rods, or that the pitchof newly formed hose can be changed by relatively turning front and rearhousings that carry front and rear bearings that support front and rearportions of the array of spinning rods that define a wrapping station.

Referring to the example illustrated in FIG. 6, a hose length 102 thatexhibits a desired straight or conical taper that transitions from arelatively smaller diameter D₁ at point A to a relatively largerdiameter D₂ at point B can be formed by first setting the rods 110 asillustrated in FIG. 7 to form the relatively smaller diameter D₁, andthen gradually and progressively moving the rods 110 until they assumethe configuration depicted in FIG. 8 to form the relatively largerdiameter D₂ to provide a hose length such as is shown in FIG. 6 asextending from points B to C. The rods 110 are then preferably movedgradually and progressively back to the configuration depicted in FIG. 7to form a reverse of the A to B taper, yielding a taper that extendsfrom points C to D, followed by the production of a length of therelatively smaller diameter hose D₁ starting at point D.

When the resulting hose shown in FIG. 6 is cut in the two indicatedplaces mid-way along the lengths that exhibit D₁ and D₂ diameters, twoidentical hoses are provided, each of which includes one of the depictedconical tapers. This technique of forming a single length of hose thatincludes a back-to-back sequence of two desired tapers (from a firstdiameter to a second, and then from the second diameter back to thefirst diameter, with the two tapered half lengths of hose then being cutapart), can be used repeatedly, yielding an extremely efficient way toproduce hoses that incorporate a desired type of single taper.

The production of hose lengths that incorporate other types of taperscan also be produced using the adjustable rods 110 to define a wrappingstation 103 where hose 102 of a desired configuration is formed. By wayof example, FIG. 9 shows a hose length 102 that incorporates a concavelycurved taper 201 that extends between points E and F, to transitionbetween a relatively smaller diameter and a relatively larger diameter.In a similar vein, FIG. 10 shows a hose length 102 that incorporates aconvexly curved taper 202 that extends between points G and H, totransition between a relatively smaller diameter and a relatively largerdiameter. FIG. 11 shows how a concave reach of hose 203 can be providedto transition between two hose lengths of substantially equal diameter;and, FIG. 12 shows how a convex reach of hose 204 can be provided totransition between two hose lengths of substantially equal diameter.

To control the apparatus 100, a conventional servo motor controller (notshown) is preferably provided that not only regulates the speed at whichthe motor 120 turns the rods 110, but also the variable settings of theservo motors 143, 153 and 160, and the parameters of operation of anextruder that extrudes the thermoplastic materials 105, 106 emitted fromthe extrusion die 107 toward the rods 110 at the wrapping station 103.To form a tapered hose such as is depicted in FIG. 6, the parametersneeded to produce the relatively smaller diameter hose D₁ at thewrapping station 103 are locked into the controller, as well as theparameters needed to produce the relatively larger hose D₂, togetherwith such information as is needed to define the taper that transitionsbetween the two diameters D₁ and D₂, and such parameters as position therods 110 to produce a hose length exhibiting a desired pitch.

The term “pitch,” as it is used in conjunction with the formation ofhelically wrapped tubing or hose, means the distance from a particularpoint on one helix or wrap, to the same particular point on an adjacenthelix or wrap—for instance, the distance from the center of one helix orwrap to the center of an adjacent helix or wrap. If the rods 110 werenot canted at all, material 105 from the extruder die 107 would wrapatop itself time and again instead of helically wrapping to form thehose 102. A small amount of canting or angulation of the rods 110 willcause the resulting helically wrapped hose 102 to have a tight pitch ofshort length. A larger amount of canting or angulation of the rods 110will produce a helically wrapped hose 102 having a wider pitch of longerlength.

To form a helically wrapped tubing or hose 102 of a certain diameterthat has a given pitch length will require a certain angulation orcanting of the rods 110. Because the spacing of the rods 110 from thecentral axis 101 (at the wrapping station 103) determines the diameterof the hose 102 that is being produced, the rods 110 are firstpositioned so that a hose 102 is produced that is found to have adesired diameter.

Once the apparatus 100 is producing hose 102 of a desired diameter, theangulation or canting of the rods 110 is adjusted (by using the motor160 to turn the rear housing 142 relative to the front housing 152) togive a rod angulation or canting that provides the resulting hose 102with a desired pitch length.

To form a taper that progressively increases or decreases the diameterof the hose 102 being produced, the rods 110 are progressively movedradially inwardly or radially outwardly to modify the diameter of theresulting hose 102 in a desired manner. However, if the pitch of thehose 102 being produced is to be maintained while a taper in diameter isprogressively being formed, it is also necessary to progressively alteror adjust the angulation or canting of the rods 110. This is because alonger amount of time and a longer length of extruded material 105 areneeded to form each wrap that is of a progressively longer length as thediameter of the hose 102 being produced is being progressivelyincreased—and because a shorter amount of time and a shorter length ofextruded material 105 are needed to form wraps that are of progressivelyshorter length as the diameter of the hose 102 being produced isprogressively diminished.

A smaller angulation or canting of the rods 110 is needed to provide agiven pitch when forming a larger diameter of tubing or hose 102; and alarger angulation or canting of the rods 110 is needed in order toprovide the same given pitch when forming a smaller diameter of tubingor hose 102. When a taper is being formed that increases the diameter ofthe hose 102, the angulation or canting of the rods 110 (that is beingprogressively adjusted by the motor 160) must decrease if the resultinghose 102 is to have a constant pitch; and, when a taper is being formedthat diminishes the diameter of the resulting hose 102, the angulationor canting of the rods 110 must increase if the resulting hose 102 is tohave a constant pitch.

In the formation of some lengths of the hose 102, it is desired thatpitch length be progressively altered to either increase or decrease.The motor 160 can be progressively used to effect such progressivechanges in hose pitch. One reason why a change of pitch may be desiredis that a tighter or shorter pitch length can provide a thicker,stronger, stiffer, more fully reinforced hose 102 that can handleincreased pressure or a vacuum of greater intensity. Another reason whya change of hose pitch may be desired is to progressively change one ora selection of characteristics such as hose thickness, hose strength,hose stiffness or hose flexibility, hose weight, and other suchcharacteristics that may be progressively changed along the length of ahose 102 being produced by the apparatus 100. For example, a relativelysmall hose diameter might be selected having characteristics of one typefor one hose region, and another region of the same hose might be formedwith a larger diameter and different characteristics.

Once the system settings have been “trimmed” by the operator to give thedesired end product, a hose will be automatically produced in acontinuous cycle first giving a hose (as shown in FIG. 6 hereof) thatexhibits a constant first relatively smaller diameter D₁ having taperedlength transitioning from the relatively smaller diameter D₁ to therelatively larger diameter D₂, and then a tapered length transitioningback from the relatively larger diameter D₂ to the relatively smallerdiameter D₁.

The tapers or changes in hose diameter that are made along particularhose lengths or reaches may be conical in nature, or may conform toother configurations that provide relatively smooth diameter changes.Lengths or reaches of hose that are of substantially constant diametermay also be provided, as a design for a particular hose application maydictate. Hoses of desired constant diameter, or of a desired taperingdiameter that changes slowly or rapidly over long or short reaches orlengths can be created, to provide an essentially limitless combinationof hose diameters and taper angles.

What is not shown by FIGS. 6 and 9-12, but will be readily apparent tothose skilled in the art, is that substantially any of the tapered formsthat are shown may be combined, as a hose designer may deem appropriatefor a particular application.

The process of the present invention works well with substantially anytraditional material from which thermoplastic hoses commonly areproduced—examples being TPC-ET, flexible polypropylene, polyethylene,polyurethane and the like. In a dual extruder arrangement where the tapematerial used to form the body of a hose and the helical reinforcingmaterial are separately extruded, the helix material would typically bea harder material relative to the material used to form the tape-likewall portion of the flexible hose being manufactured.

The flexible hose formed herewith can, for example, have a hose walldefined by a thin, narrow, elongate web formed from PVC, TPU, PP, TPE orABS material, and can, for example, employ a helical reinforcing spiralthat is formed from PVC, TPU, PP, TPE or ABS material.

Textiles can be substituted for the wall-forming tape-like material, anda coated or uncoated wire can be used to form the reinforcing helix ofthe hose being manufactured. Any color or additive can be added to theplastic to give custom properties or appearance.

As is well known in the art of hose production, a so-called “crush cuff”of substantially uniform diameter can be provided where newly producedhose lengths are to be severed, thus providing newly produced hoselengths with regions that are well suited to join or mate with existingfittings or rigid conduits, which can be held in place by means offriction or through the use of any of a wide variety of known hoseclamps and other mechanical contrivances. A typical cuff such as can beprovided on a length of hose produced using techniques of the presentinvention is indicated by the numerals 18a and 18b in FIG. 4 of U.S.Pat. No. 7,014,449 issued Mar. 21, 2006 to Mark Woelfel, the disclosureof which is incorporated herein by reference. The referenced Stewardpatents also show the positioning of a roller 44 near where extrudedthermoplastic material is wound about a plurality of spinning rods—aroller 44 that can be used to periodically flatten a reinforcing bead orrib to periodically provide cuffs that have no upstanding reinforcingbead or rib, and that may therefore be joined easily with existingfittings and the like.

If desired, features of the present invention may be practiced byreplacing the smooth rods 110 that spin (about which the tape-likematerial is wound to form the flexible wall of the hose at the wrappingstation 103) with contoured shafts that create hose profiles that aredesigned to increase the stretch ratio of the resulting hose.

In accordance with the invention described in an earlier-filedapplication Ser. No. 12/799,263 filed Apr. 21, 2010 by Martin E.Forrester et al entitled FLEXIBLE, STRETCHABLE, CRUSH RESISTANT HOSEWELL SUITED FOR MEDICAL APPLICATIONS, and its predecessor applicationSer. Nos. 12/354,291 and 61/335,023, the disclosures of all of which areincorporated herein by reference, in their entireties), tubing or hoselengths, or portions, regions or reaches thereof that are produced inaccordance herewith may be compressed and annealed to impartultra-flexible reaches with stretch ratios that are increased. Suchstress-relieved hose reaches are particularly desirable in medicalapplications where undesirably stiff hoses may cause breathing masks toleak or move out of place, or may cause connections between tubing orhoses or components of tubing or hose circuitry to disconnect.

Utilizing features of the present invention, hose can also bemanufactured with multiple starts, where two or more helical beads areused along with a tape-like band that is wide enough to span the entirewidth of the desired profile plus the necessary extra width to bond theprofile beneath or overlying the helix to create a smooth hose. Multiplestarts also allow the hose to be manufactured more quickly as the hoseprogresses down the length of the spinning rods two or more pitches perhose revolution. Further, multiple starts also allows for differentmaterials to be used in the helical portion for color coding, or toprovide other unique physical properties.

In some embodiments of the invention, multiple start helices (not shown)can be utilized (i.e., by using plural, side-by-side, simultaneousextrusions of hot tape-like bands of thermoplastic that wrapside-by-side so that overlapping edge portions of adjacent tape-likebands bond to form a hose wall), thereby resulting in a production speedthat is increased by a factor equal to the number of multiple starts perhose revolution.

In some embodiments of the invention, the rate at which the rods arespun, turned or rotated is adjusted so that the angular velocity of theouter surfaces of the rods is preferably maintained at not less than thevelocity at which hot thermoplastic material is extruded toward thewrapping station. In accordance with other embodiments, the surfacespeed of the outer surfaces of the rods may be adjusted to achieve adesired stretching or “draw down” of the molten tape-like band and/orthe wire-like bead of the hot, freshly extruded thermoplastic so as tocause the newly formed hose to exhibit desired dimensions such as aparticular desired thickness, or to exhibit desired characteristics ofstrength as chains of molecules become suitably oriented duringformation of the newly formed hose wall and its helical reinforcement.

The present invention preferably provides an electro-mechanical systemthat repositions the spinning rods as hose is formed, to thereby createtapered lengths or reaches of hose, or hose that has tapered lengths orreaches between substantially straight lengths or reaches ofsubstantially constant diameter that typically may be of differingdiameters. The process used can be continuous in nature, repeating atpre-determined intervals to create hose with one starting diameter andlength, followed by a tapered section of desired length, followed by anending diameter and length—whereafter the process is reversed to createsubstantially the same piece of hose that transitions from the endingdiameter and length to the starting diameter and length, with cuttingsbeing made at locations selected to give two exactly identical pieces ofhose. In much the same manner, the a hose being manufactured can besevered at various pre-determined positions to create desired discretehose lengths consisting of one or more straight or constant diametersections with one or more tapered sections therebetween, as a particularhose design dictates.

Among features of the present invention (that are in no way taught orsuggested by the prior art) is an arrangement for movably supporting theindividual rods in bearings that not only permit the rods to turn, spinor rotate, but also permit the rods to be concurrently radially movedcontinuously and progressively during formation of at least a continuousportion, region or reach of a length of thermoplastic tubing or hosethat is being formed at a wrapping station, so that at least theresulting portion, region or reach of tubing or hose changessubstantially continuously and progressively in diametrical size—so theresulting portion, region or reach of tubing or hose tapers as may bedesired, for example to provide an appearance that is of truncatedconical shape, or a configuration that is characteristically concave,convex or bulbous in appearance, or changes in some other way from onediameter to a different diameter.

As those skilled in the art will readily appreciate, the methods ortechniques described herein can be used to provide tubing or hoselengths that have portions, regions or reaches of constant diameter (bymaintaining the positions held by the rods such as is described in thetwo referenced Steward patents), and that have portions, regions orreaches that progressively change in diametrical size (by progressivelymoving the rods so that their positions relative to an imaginary centeraxis about which newly formed hose moves away from a wrapping station).Causing the rotating, turning or spinning rods of the rod array to bespaced farther from the center axis will cause hose being produced tohave a relatively larger diameter or size. Causing the rods of the arrayto be spaced closer to the center axis will cause the tubing or hosebeing produced to have a relatively smaller diameter or size.

The method just described can be used to continuously produce reaches orlengths of helically reinforced flexible tubing or hose that exhibit aplurality of differing diameters, with transitional portions, regions orreaches that smoothly connect the differing diameters by means ofconical tapers or tapers that feature other relatively smooth,continuous and progressive, curved or perhaps even elliptical areas oftransition.

The heated, freshly extruded tape-like and wire-like thermoplasticmaterials that are helically wrapped to form a helically reinforcedflexible hose in accordance with some embodiments of the invention 1)may be concurrently extruded from a single extrusion apparatus using asingle extrusion die as a unified band of thermoplastic, 2) may beco-extruded from a single extrusion die using two or more extruders toprovide thermoplastic materials to form a, hose comprised of multiplematerials having different properties (such as different stiffness,fatigue resistance, chemical resistance, or other physical properties),or 3) may be simultaneously extruded from separate extruders throughseparate extrusion dies so that the wall and reinforcing helix of theresulting hose are comprised of different materials that preferably arecaused to bond as they are laid together at and move away from thestationary array of spinning rods at a wrapping station.

In accordance with some embodiments of the invention, continuous,pre-extruded tapes, fabrics, wire-like beads and the like can beutilized if they are heated before being brought together and wrappedabout an array of spinning rods as described above, with heat beingprovided by a conventional external heat source (not shown) such as hotair to render bondable the materials that form a continuous tubing orhose wall and a continuous reinforcing helix bonded continuously to thehose wall. In some embodiments, adhesives also may be used to create abond between materials that are wrapped about an array of spinning rodssuch as is described above to create a desired tubing or hose profilethat spins about an imaginary central axis as it moves away from awrapping station (as do all hose embodiments formed at a wrappingstation defined by an array of spinning rods in accordance herewith).

Although the invention has been described in its preferred form with acertain degree of particularity, it is understood that the presentdisclosure of the preferred form has been made only by way of example,and that numerous changes in the details of construction and thecombination and arrangement of parts and techniques may be resorted towithout departing from the spirit and scope of the invention ashereinafter claimed. It is intended to protect whatever features ofpatentable novelty that exist in the invention disclosed.

The invention claimed is:
 1. A method of forming a length of helicallyexternally ribbed plastic tubing, comprising the steps of: a) providinga plurality of elongate rods that are canted relative to an imaginarycentral axis and that converge as the rods approach a wrapping stationat a location along the central axis, with each rod having a differentcenterline about which the rod is individually turned at a same speed ofrotation and in a same clockwise or counterclockwise direction ofrotation; b) continuously extruding both a tape-like web ofthermoplastic material and a bead of thermoplastic material toward thewrapping station; c) continuously helically winding both 1) thetape-like web of thermoplastic material and 2) the bead of thermoplasticmaterial circumferentially around the plurality of turning rods at thewrapping station so that the tape-like web of thermoplastic materialforms a continuous tubular wall of the length of tubing that advancesaway from the wrapping station along the central axis as the continuoustubular wall is formed, with one edge region of each newly woundconvolution of the tape-like web overlapping and bonding to an adjacentpreviously wound convolution of the tape-like web to thereby form thecontinuous tubular wall, and so that the bead of thermoplastic materialforms a rib that is integrally connected to and helically woundexternally about the tubular wall to provide reinforcement thereto; d)progressively concurrently radially moving the turning rods transverselyrelative to the central axis during winding of the thermoplasticmaterials of the web and the bead at the wrapping station toprogressively alter the diameter of a continuous portion of the lengthof tubing as the length of tubing is formed at the wrapping station; ande) annealing, while axially compressed, at least a selected portion ofthe length of tubing to relieve stress and enhance flexibility of theselected portion.
 2. The method of claim 1, wherein the continuousportion with the progressively altered diameter and the selected portionthat is annealed at least partially coincide.
 3. The method of claim 1,wherein the continuous portion with the progressively altered diameterand the selected portion that is annealed are at least partiallyseparate portions of the length of tubing.
 4. The method of claim 1,including the step of periodically flattening the rib of the length oftubing at locations spaced along the central axis from the wrappingstation, as the length of tubing is formed, to provide spaced,longitudinally extending regions of the length of tubing that have awall thickness greater than is formed by wrapping the tape-like web ofthermoplastic material about the turning rods at the wrapping station.5. The method of claim 4, additionally including the step ofperiodically cutting the length of tubing transversely relative to thecentral axis at locations intermediate the spaced, longitudinallyextending regions as the length of tubing is formed.
 6. The method ofclaim 1, additionally including the step of periodically transverselycutting the length of tubing as the length of tubing is formed.
 7. Themethod of claim 1, additionally including the step of adjusting thespeed of rotation of the rods relative to a speed at which thethermoplastic materials of the web and bead are extruded toprogressively alter a characteristic of the length of tubing as thelength of tubing is formed, wherein the characteristic is selected froma group consisting of tubing pitch, strength, flexibility, stiffness,wall thickness and helix size.
 8. The method of claim 1, additionallyincluding the step of adjusting at least one of the speed of rotation ofthe rods or a pitch of the length of tubing to progressively alter acharacteristic of the length of tubing as the length of tubing isformed, wherein the characteristic is selected from a group consistingof tubing strength, flexibility, stiffness, wall thickness, helix sizeand weight.
 9. The method of claim 8, wherein: the speed of rotation ofthe rods is decreased as the diameter of the length of tubing isincreased as the length of tubing is formed; and the speed of rotationof the rods is increased as the diameter of the length of tubing isdiminished as the length of tubing is formed.
 10. The method of claim 1,wherein: the number of rods at the wrapping station is increased as thecontinuous portion is formed if the continuous portion comprises atransition from a smaller diameter to a larger diameter; and the numberof rods at the wrapping station is decreased as the continuous portionis formed if the continuous portion comprises a transition from a largerdiameter to a smaller diameter.
 11. The method of claim 1, wherein, asthe diameter of the continuous portion is progressively changed as thecontinuous portion is formed, the extent to which the rods are cantedrelative to the central axis is also progressively changed as thecontinuous portion is formed.
 12. The method of claim 11, wherein theextent to which the rods are canted relative to the central axis isprogressively changed as the continuous portion is formed so that acharacteristic of the continuous portion remains substantially constantalong the length of tubing, wherein the characteristic is selected froma group consisting of tubing pitch, strength, flexibility, stiffness andwall thickness.
 13. The method of claim 11, wherein the extent to whichthe rods are canted relative to the central axis is progressivelychanged as the continuous portion is formed so that a characteristic ofthe continuous portion is caused to progressively change along thelength of the tubing, wherein the characteristic is selected from agroup consisting of tubing pitch, strength, flexibility and wallthickness.
 14. The method of claim 1, wherein, as the length of tubingis formed, operation of an apparatus that concurrently turns andrepositions the rods is progressively altered to progressively change atleast one characteristic of the length of tubing along the length oftubing, wherein the at least one characteristic is selected from a groupconsisting of tubing pitch, tubing strength, tubing flexibility, tubingwall thickness, tubing helix size, tubing stiffness, tubing weight, aflow performance characteristic of flow velocity, and a flow performancecharacteristic of flow pressure.
 15. A method of continuously forming ahelically reinforced, flexible hose from continuously extrudedthermoplastic material, the method comprising the steps of: helicallycircumferentially wrapping the extruded thermoplastic material at awrapping station around an array of concurrently turning,bearing-supported rods that are canted relative to an imaginary centralaxis, with the hose being formed having a continuous tubular hose wallthat has a continuous reinforcing rib extending helically therearoundand continuously integrally connected thereto; progressively alteringthe relative positions of the rods during formation of at least acontiguous portion of the hose to cause the contiguous portion toexhibit a progressive change in diameter; and axially compressing andannealing at least a selected portion of the hose to relieve stress andenhance flexibility of the selected portion.
 16. The method of claim 1,wherein: the extruded thermoplastic material of the tape-like webcomprises at least one of polyvinyl chloride (PVC), thermoplasticpolyurethane (TPU), polypropylene (PP), thermoplastic elastomer (TPE) oracrylonitrile butadiene styrene (ABS) material; and the extrudedthermoplastic material of the reinforcing rib comprises at least one ofPVC, TPU, PP, TPE or ABS material.
 17. The method of claim 15, whereinthe progressive change in diameter of the contiguous portion isperformed so as to provide the hose wall of the contiguous portion witha region of bulbous form.
 18. The method of claim 15, wherein one of thecontiguous portion and the selected portion comprises at least part ofthe other of the contiguous portion and the selected portion.
 19. Themethod of claim 15, further comprising the step of progressivelyaltering at least one of a speed at which the rods are concurrentlyturned or a pitch of the contiguous portion while the positions of therods are being progressively altered to progressively change acharacteristic of the contiguous portion, wherein the characteristic isselected from a group consisting of hose pitch, hose strength, hoseflexibility, hose wall thickness, hose stiffness and hose weight. 20.The method of claim 15, wherein the progressive change in diameterprovides the hose wall of the contiguous portion with at least a regionof progressively diminishing diameter or increasing diameter.
 21. Themethod of claim 15, wherein the progressive change in diameter isperformed so as to provide the hose wall of the contiguous portion witha region that has a tapering change in diameter that is either concaveor convex.
 22. The method of claim 15, wherein the contiguous portionhas a characteristic that progressively changes along the length of thecontiguous portion, wherein the characteristic is selected from a groupconsisting of hose pitch, hose strength, hose flexibility, hose wallthickness, hose stiffness, hose weight, a flow performancecharacteristic of flow velocity, and a flow performance characteristicof flow pressure.